Radiator cap



June 9, 1964 R. R. MITCHELL 3,136,292

RADIATOR CAP Filed May 24, 1962 INVENTOR. RAYMOND R. M/TGHELL UnitedStates Patent 3,136,292 RADIATOR CAP Raymond R. Mitchell, Lake County,Ind. (2304 E. 73rd St., Crown Point, Ind.) Filed May 24, 1962, Ser. No.197,566 2 Claims. (Cl. 116114) a reduced section in the form of anannular seat against which the axially movable seal closure of theradiator cap is seated ,by a coil spring which encircles a center stemor a collar connecting the cap member and the seal closure. This centercollar of the conventional radiator cap is connected to the cap memberhaving interposed therebetween a freely rotatable diaphragm which servesas a base for confining the coil spring between the cap member and theaxially movable seal closure and prevents relative angular movementbetween the ends of the spring while the cap is rotated relative to theseal closure. The axially extending flange of the cap member engages thecamming edges of the spout to tighten the cap to the spout.

The coil spring holding the seal closure against the annular seat in thespout responds to a predetermined pressure ranging from approximatelylOp.s.i. to psi. above atmosphere so that when the vapor pressure in theradiator has increased due to the increase in temperature of the liquidcoolant to a point which exceeds this predetermined pressure setting,the seal closure will be lifted from the annular seat to allow theexcess pressure to escape to atmosphere.

The particular problem to which this invention is directed is the escapeof coolant vapor, and the liquid coolant with the escaping vapor, fromthe radiator of an automobile when the radiatorcap is removed while thevapor'pressure in the radiator is greater than atmosphere. The radiatorcap is removed regularly as part of the service routine rendered theautomobile each time the automobile is stopped for refueling. Not onlyis some of the liquid in the radiator lost each time the radiator cap isremoved during these service stops, but'also the removal of the capwhileunder pressure is a serious safety hazard, particularly .sincethe highpressure seal closures.

common on the newer automobiles results in a higher operatingtemperature of the liquid coolant.

Accordingly, a principal object of my invention is to provide a radiatorcap, the parts of which are. of such construction and arrangement thatthe liquid'coolant is automatically raised-from the radiator by theincreased vapor pressure therein to a reservoirin the radiator capsothat the liquid coolant may be observed and the radiator cap need not beremoved while under pressure if it is not necessary.

Another object of my invention'is to-provide a radiator cap which hascommunicating passageways between the radiator and the reservoirincluded therein and alsov be scription and drawings which illustrate apreferred embodiment thereof, wherein:

FIGURE 1 is a sectional elevation of the radiator cap.

embodying my invention connecting the radiator spout including afragmentary part of the radiator and showing the tubular passagewaysubmerged in the liquid coolant to a preselected level,

FIGURE 2 is a sectional elevation of the present invenf tion showing thetubes above the liquid coolant level which occurs when the level hasreceded below the preselected level, and

FIGURE 3 is a plan elevation of the radiator ,cap of my invention.

Referring more particularly to the drawings, numeral 10 designates theconventional automobile radiator, shown in fragment, with which isassociated a conventional filler spout 12 having interior thereof, atoneend, an annular seat 14; AXially-spaced from seat 14 and exterior ofspout 12 at the other end thereof are provided inclined edges 16 and18.. Overflow pipe 20 is conventionally provided to communicate theinterior of the spout to atmosphere and is located between the annularseat 14 and the other end thereof.

My cap assembly, designated generally by the numeral 22, comprises a capmember 24 having an axially extending flange 26. The lower edge 28 offlange 26 has two or more inturned strips 30 adapted to engage theinclined edges 16 and 18 of spout 12 which, by rotational movement ofthe cap member 24, wedges the cap 22 against the spout 12. Cap member 24has a central opening 32 which receives a cylindrical reservoir chamber34. One end of reservoir member 34 is closed by a circular disc 38having a peripheral portion overlapping the annular seat 14 interior ofthe spout 12. The peripheral portion of the disc 38 overlapping theannular seat 14 is provided with a seal diaphragm 40 so that sealcontact may be made between disc 38 and annular seat 14. End 42 ofreservoir chamber 34 passes through opening 32 of cap member 24 and isaxially slidable to and fro therein. Helical or coil spring 44 surroundsreservoir chamber 34 and is confined between disc 38 at one end and capmember 24 at the other end. Spring 44 serves to urge disc member 38.away from cap member 24. When'the cap assembly 22 is mounted on spout 12of radiator 10, spring 44 urges disc 38 including seal diaphragm 40against annularseat 14 thereby providing a valved closure for theradiator. I also show abearing diaphragm 46 interposed between the capmember 24 and spring 44 on reservoir chamber 34-which is free to rotaterelative to cap member 24. Bearing diaphragm 46 serves to frictionallyengage the end of .spout 12 and provide a seat for spring 44 at one or"the ends thereof. Bearing diaphragm 46 remains stationary while capmember 24 rotates relative to spout 12. The opposite ends of spring 44are thereby preventedv from engaging relative rotating confining seatswhich would, in eifect, wind or unwind the helix of spring 44 and affectthe constancy of the spring pressure. Bearing diaphragm 46 also preventsthe tendency ofseal diaphragm 40 to rotate-against the annular seat 14which otherwise would cause. excessive wear of the seal diaphragm. The.bearing diaphragm feature, however, is well known inthe art and is not apart of the present invention.

The other end 42 of cylindrical reservoir chamber 34 extendingthroughopening 32 in cap member 24 -is provided with threads or any othersuitable means for fastening thereto a transparent cover 50. I providetransparent cover 50 mounted on end 42 of reservoir chamber 34 with aseal 52 therebetween and held tight thereto by means of a threaded ring54. The threaded ring 54 will also serve to provide an abutment for capmember 24 Patented June 9, 1964.

3 which is urged outwardly by spring 44 and thereby also serves tofasten the parts of the present radiator cap 22 in assembled relation.

The reservoir member 34 is provided with a one-way valve 56 preferablyadjacent the top end thereof. I show valve 56 as comprising a ballseated against a vent aperture by spring means in a housing which isclamped in an opening in a transparent cover 50.

Circular disc 38 has an aperture 58 fitted with a short tube 60 ofpreselected length. Tube 60 terminates in the reservoir chamber 34adjacent the disc 38. The preselected length of tube 60 is sufficient tosubmerge the free end thereof in the liquid coolant when the coolant isat normal operating level in the radiator as shown in FIGURE 1. A secondtube 62 is fixed to a second aperture 64 in disc 38 adjacent tube 60.End 66 of tube 62 extends into the reservoir chamber 34 above tube 60.

In operation, the radiator cap 22 embodying the present invention isfastened to the automobile radiator 10 in the customary manner. The freeend of tubes 60 and 62 are submerged to a predetermined level in theliquid coolant below which the level of the liquid in the radiator isdeemed low and will require replenishing. As the internal combustionengine warms up to operating temperature the vapor pressure in theradiator 10 increases due to the increase in temperature of the liquidcoolant. This vapor pressure, as stated above, will increase to thelimit imposed by spring 44 on seal closure disc 38. The interior ofreservoir chamber 34 being valved as at 56 to atmosphere, a pressuredifferential will exist between the radiator 10 and the reservoirchamber. With tubes 60 and 62 providing passageways communicatingreservoir chamber 34 and radiator 10, liquid coolant will pass throughtubes 60 and 62 to fill the reservoir chamber 34. The atmosphere inchamber 34 will be compressed by the liquid coolant as it enters thereservoir chamber until the pres sure of the atmosphere thereincounterbalances the vapor pressure in radiator 10 at which time the fiowof liquid from radiator 10 to reservoir chamber 34 through tubes 60 and62 will stop. Therefore, as long as the pressure in radiator 10 isgreater than atmosphere and the liquid coolant in radiator 10 is atnormal level, that is above tubes 60 and 62, the liquid coolant willrise to the reservoir chamber 34 and be observable therein throughtransparent cover 50, and it will not be required to remove radiator cap22 to observe whether there is sufiicient liquid coolant in theradiator. When the liquid level in the radiator 10 drops below the tubes60 and 62 as shown in FIGURE 2, the liquid in the reservoir chamber 34will drain into the radiator 10 through the tube 60. Any pressuredifferential between chamber 34 and radiator 10 Will have been equalizedby tube 62 which serves to facilitate the drainage of liquid fromreservoir chamber 34 to radiator 10. An empty reservoir chamber 34 whenthe radiator is heated to operating temperature will, of course,indicate that the liquid level in the radiator is below normal level andwill require replenishing. Necessary precautions may then be taken whenremoving the radiator cap 22. An empty reservoir chamber when theradiator is cool such as when the automobile engine has not beenrunning, does not indicate that the liquid coolant in the radiator isbelow the normal level since there is no pressure differential betweenthe radiator 10 and the reservoir chamber 34 to cause the liquid in theradiator to rise to the reservoir chamber and any liquid in thereservoir chamber will have normally drained back into the radiator.However, under this condition, the radiator cap 22 may be removedwithout liquid coolant loss. Valve 56 is provided to allow air to enterreservoir chamber 34 when the pressure therein drops below atmosphere.This will occasionally occur due to the fact that some liquid coolantwill be lost and upon condensation due to cooling the pressure inradiator 10 will drop below atmosphere since a larger volume is thenavailable.

It is apparent from the above full and complete description that myinvention constitutes a novel improvement over the prior art in that myinvention prevents loss of liquid coolant by eliminating the unnecessaryremoval of the radiator cap to ascertain the coolant level in theradiator. Also, my improvement may be easily combined with theconventional radiator cap without radically changing the manufacturingmethod employed for the conventional radiator caps.

Though I have described a single preferred embodiment of my invention,it is realized that changes and modifications may be made in the deviceby those skilled in the art Without departing from the spirit of theinvention. Therefore, what I claim as my invention is set out in theappended claims.

I claim:

1. For a vehicle radiator and the like having a filler spout providedwith an annular seat therein; a valve closure comprising, an annular capmember adapted for retaining engagement with said spout, a sleeve memberaxially slidable through said annular cap member, a closure for one endof said sleeve member, said closure comprising a resilient peripheralportion for seal contact with said annular seat of said spout, a tubecommunicating the interior of said sleeve member at said one end thereofextending longitudinally exterior of said sleeve member, a second tubeextending longitudinally exterior of said sleeve member and extendinglongitudinally interior thereof communicating the interior of saidsleeve member forward of said first tube at said one end of said sleevemember, a closure for the other end of said reservoir, said secondclosure being transparent and having valve means communicating theexterior of said sleeve member and the interior thereof, and springmeans seated on said cap member for holding said first mentioned closureof said sleeve member in seal contact with said annular seat.

2. For a vehicle radiator and the like having a filler spout providedwith an annular seat therein; a cap comprising, a ring member adaptedfor retaining engagement with said spout, a reservoir member axiallyslidable through said ring member, a closure for one end of saidreservoir member, said closure comprising a resilient peripheral portionfor seal contact with said annular seat of said spout, a tubecommunicating the interior of said reservoir member at said one endthereof and extending longitudinally exterior of said reservoir member,a second tube of reduced dimension in said first mentioned tubeextending longitudinally interior of said reservoir member communicatingthe interior thereof forward of said first tube at said one end of saidreservoir member, a closure for the other end of said reservoir member,said second closure being transparent, means for connecting said secondclosure to said tubular member, said connecting means providing anabutment for said ring member, and resilient means confined between saidring member and said first mentioned closure for urging said firstmentioned closure away from said ring member.

Swank July 2, 1935 Danias June 24, 1958

1. FOR A VEHICLE RADIATOR AND THE LIKE HAVING A FILLER SPOUT PROVIDEDWITH AN ANNULAR SEAT THEREIN; A VALVE CLOSURE COMPRISING, AN ANNULAR CAPMEMBER ADAPTED FOR RETAINING ENGAGEMENT WITH SAID SPOUT, A SLEEVE MEMBERAXIALLY SLIDABLE THROUGH SAID ANNULAR CAP MEMBER, A CLOSURE FOR ONE ENDOF SAID SLEEVE MEMBER, SAID CLOSURE COMPRISING A RESILIENT PERIPHERALPORTION FOR SEAL CONTACT WITH SAID ANNULAR SEAT OF SAID SPOUT, A TUBECOMMUNICATING THE INTERIOR OF SAID SLEEVE MEMBER AT SAID ONE END THEREOFEXTENDING LONGITUDINALLY EXTERIOR OF SAID SLEEVE MEMBER, A SECOND TUBEEXTENDING LONGITUDINALLY EXTERIOR OF SAID SLEEVE MEMBER AND EXTENDINGLONGITUDINALLY IN-